Oddly enough, after Kaizen and Linus entered the dark room guarded by the rune door and saw the hooded old man, no boss health bar or notification appeared.
Kaizen was confused and a little disappointed because he could have sworn this was a boss room. So he used his <Analyzing Eye> to find out what he was up against.
[Creature: Mysterious Old Man
Level: 1 | Attribute: Human | Nature: Primal
HP: 100 | MP: 1
Attack: 1 | Defense: 1 | Speed: 1
Strength: 1 | Wisdom: 100 | Resistance: 1
Resistance to spells of: None]
"Who are you?" asked Linus in a firm voice, already suspicious as usual. "And what do you want?"
The old man smiled slowly. "I am the guardian of this labyrinth, and I am here to test your courage and skill," he replied in a gruff, dark voice. "If you wish to continue, you will have to face a challenge."